The present invention relates to coating compositions for flexible, sheet-like substrates, coated flexible, sheet-like substrates for articles of manufacture used in contact with human body surfaces, and a process for adding waxy compositions to flexible, sheet-like substrates. The present invention is particularly useful for coating compositions for flexible, sheet-like substrates, coated flexible, sheet-like substrates used in the manufacture of disposable absorbent articles, specifically suited for coated flexible, sheet-like substrates used in the manufacture of tampons.
There are several methods of delivering waxy compositions to their intended targets, including but not limited to oral, topical, and transdermal methods. Disposable absorbent articles can be used as vehicles for topical delivery to the vaginal canal, perineum, and related areas, as well as for treatment sites for the discharged fluids to come in contact with the waxy compositions, as they are captured by the product.
Waxy materials tend to be somewhat tacky, and difficulties arise in particular with regard to the handling of sheets coated or impregnated with such waxy materials during their production. The sheet and its waxy material tend to stick to machine parts and to foul the machinery with consequent process interruption and time loss due to machinery down-time and maintenance.
GB 2287481 purports to disclose a process for manufacturing a wax impregnated cloth material. In this process, a cloth web is led through a bath of liquid wax. The web is then led to remote cooling rollers. As the web travels to the cooling rollers, a fan directs a cooling air stream along an upper face of the web. The web is further cooled around the cooling rollers. Circulating a refrigerant therethrough cools all of the cooling rollers. The cooled web is then wound up at a reeling station.
Yang, U.S. Pat. No. 6,316,019 discloses a process for making a tampon including the application to a substrate of a solution containing a pharmaceutically active compound. The solution is liquid at a temperature of less than about 35° C., and it is applied to the disposable absorbent article at a temperature of less than 40° C. While this is an advance in the art, the ability to add substantial amounts of the pharmaceutically active compound to the substrate to form a robust and flexible coated material is limited.
The present invention is directed towards overcoming these problems, and to provide a process for manufacturing sheets coated or impregnated with such waxy materials that is efficient and trouble free in operation.